In the 3rd Generation Partnership Project (3GPP), utilizing a radio access system and evolution of radio network of cellular mobile communication (referred to as “LongTerm Evolution (LTE)” or “Evolved Universal Terrestrial Radio Access (EUTRA)” in the following), and a wider frequency band, a radio access system and radio network are under consideration which realize faster data communication (referred to as “Long Term Evolution-Advanced (LTE-A, A-LTE)” or “Advanced Evolved Universal Terrestrial Radio Access (A-EUTRA)” in the following).
In LTE, as a downlink (radio communication from a base station apparatus to a mobile station apparatus), Orthogonal Frequency Division Multiplexing (OFDM) method is used, which is multi-carrier transmission. In addition, as an uplink (radio communication from a mobile station apparatus to a base station apparatus), SC-FDMA (Single-Carrier Frequency-Division Multiple Access) method is used, which is single-carrier transmission.
FIG. 18 illustrates a downlink radio frame structure in LTE. In the downlink, a Physical Downlink Control Channel (PDCCH), a Physical Downlink Shared Channel (PDSCH), or the like are mapped. In addition, a downlink reference signal is mapped to a part of the PDSCH. In addition, a downlink radio frame includes a downlink Resource Block (RB) pair.
The downlink RB pair, which is a unit of RB used when assigning a downlink radio resource, includes a frequency band (RB bandwidth) with a predetermined width and a time zone (2 slots=1 subframe). A downlink RB pair includes two downlink RBs (RB bandwidth×slot) which are contiguous in the time domain.
For example, a downlink RB includes 12 subcarriers in the frequency domain and includes seven OFDM symbols in the time domain. Here, a PDCCH is a physical channel which carries a mobile station identifier, scheduling information of a PDSCH, scheduling information of a Physical Uplink Shared Channel (PUSCH), Modulation and Coding Scheme (MCS) information (modulation scheme and coding rate), retransmission parameter information or the like, and which carries Downlink Control Information (DCI). Here, a mobile station identifier, which is, for example, a C-RNTI (Cell-Radio Network Temporary Identifier), is an identifier effective only within a cell managed by a base station apparatus. The C-RNTI is assigned to a mobile station apparatus by the base station apparatus. In addition, scheduling information of a PDSCH may include RB assignment information for the PDSCH. In addition, scheduling information of a PUSCH may include RB assignment information for the PUSCH.
FIG. 19 illustrates an uplink radio frame structure in LTE. In the uplink, a Physical Uplink Control Channel (PUCCH), a Physical Uplink Shared Channel (PUSCH), or the like are mapped. In addition, an uplink reference signal is mapped to a part of the PUSCH and PUCCH. In addition, an uplink radio frame includes an uplink RB pair.
The uplink RB pair, which is a unit of RB used when assigning an uplink radio resource, includes a frequency band (RB bandwidth) with a predetermined width and a time zone (2 slots=1 subframe). For example, an uplink RB pair includes two uplink RBs (RB bandwidth×slot) which are contiguous in the time domain. In addition, for example, an uplink RB includes 12 subcarriers in the frequency domain and includes 7 SC-FDMA symbols in the time domain.
FIG. 20 is a schematic view illustrating reporting (feedback) of Channel Statement information (CSI) in LTE. Here, the channel state information includes a Channel Quality indicator (CQI).
A base station apparatus 2001 notifies a mobile station apparatus 2002 of DCI 2003 including uplink scheduling information (RB assignment information) indicating on which RB the mobile station apparatus 2002 transmits an uplink transmission signal 2004 including the channel state information. Based on the DCI notified from the base station apparatus 2001, the mobile station apparatus 2002 transmits the uplink transmission signal 2004 including the channel state information to the base station apparatus 2001.
FIG. 21 illustrates an exemplary configuration of a Downlink Control Information Format (DCI format) in LTE. As described in Non-patent document 1, a plurality of bit fields (information fields) is defined in a DCI Format0 including uplink-related information such as uplink scheduling information.
As illustrated in FIG. 21, for example, the leading bit field of the DCI Format0 includes a flag (Flag for Format0/Format1A) for distinguishing between the Format0 and Format1A which is another downlink control information format. The mobile station apparatus recognizes (identifies) the configuration of subsequent bit fields by first checking the flag for distinguishing between the Format0 and Format1A.
In addition, the DCI Format0 includes (is formed by) a bit field indicating uplink scheduling such as Hopping flag, RB assignment (Resource Block assignment) information or the like, a bit field for MCS (Modulation and Coding Scheme) and RV (Redundancy Version) indicating the modulation scheme, coding rate, retransmission parameters or the like, a bit field for New Data Indicator indicating whether the transmission is an initial transmission or a re-transmission, a bit field for CQI request indicating whether or not reporting of the channel state information (the channel quality indicator) is requested (bit field indicating whether or not a transmission of the channel state information (the channel quality indicator) is instructed), or the like.
For example, when the CQI request field of the DCI Format0 transmitted from the base station apparatus indicates a state in which reporting of the channel state information is performed (e.g., when the CQI request field is set to “1”), the mobile station apparatus transmits an uplink transmission signal including the channel state information to the base station apparatus.